<html><head><meta http-equiv="Content-Type" content="text/html; charset=utf-8"></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; line-break: after-white-space;" class="">As a supplement to Giuseppe’s and Lorenzo's comments:<div class=""><br class=""><div class="">1- forc_conv_thr should be smaller: about 1e-4 or 1e-5 (why using 1.94469e-03 with that many digits?)</div><div class="">2- add: etot_conv_thr= 1e-7</div><div class="">2- I would use ibrav=0 together with CELL-PARAMETERS (see online manual)</div><div class="">3- occupation=fixed, no smearing, and nbnd=number of occupied states+ a few virtual ones. It should work as you have a dimer.</div><div class="">4- why using vdW corrections? not sure they are significant. Furthermore, as a remember Grimme’s corrections are not that good for metals. I got too large bond distances for gold (but it was for a solid)… </div><div class="">5- mixing_beta=0.2 should do the job and you eventually avoid oscillations in the SCF convergence if you use a too large value (or even no convergence at all).</div><div class="">6- &CELL … / section is not necessary as you only optimise atomic positions.</div><div class="">7- K_POINTS {Gamma} is all right as you have a molecule (k-points are only meaningful for slabs and bulk structures)</div><div class=""><br class=""></div><div class="">HTH,</div><div class="">Best</div><div class=""><br class=""></div><div class=""><br class=""><div class="">
<div dir="auto" style="caret-color: rgb(0, 0, 0); color: rgb(0, 0, 0); letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration: none; word-wrap: break-word; -webkit-nbsp-mode: space; line-break: after-white-space;" class=""><div dir="auto" style="caret-color: rgb(0, 0, 0); color: rgb(0, 0, 0); letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration: none; word-wrap: break-word; -webkit-nbsp-mode: space; line-break: after-white-space;" class=""><div dir="auto" style="text-align: start; text-indent: 0px; word-wrap: break-word; -webkit-nbsp-mode: space; line-break: after-white-space;" class=""><div class="" style="caret-color: rgb(0, 0, 0); color: rgb(0, 0, 0); letter-spacing: normal; text-transform: none; white-space: normal; word-spacing: 0px; text-decoration: none; -webkit-text-stroke-width: 0px;"><span class="" style="font-size: 16pt; font-family: Mistral;">Pascal Boulet</span></div><div class="" style="caret-color: rgb(0, 0, 0); color: rgb(0, 0, 0); letter-spacing: normal; text-transform: none; white-space: normal; word-spacing: 0px; text-decoration: none; -webkit-text-stroke-width: 0px;"><font face="Lucida Handwriting" class=""><span class="" style="font-size: 21px;">—</span></font></div><div class="" style="caret-color: rgb(0, 0, 0); color: rgb(0, 0, 0); letter-spacing: normal; text-transform: none; white-space: normal; word-spacing: 0px; text-decoration: none; -webkit-text-stroke-width: 0px;"><em class="" style="color: rgb(34, 187, 234); font-family: verdana; font-size: 11px; line-height: 22px;">Professor in computational chemistry - DEPARTMENT OF CHEMISTRY</em></div><div class=""><div class="" style="caret-color: rgb(0, 0, 0); color: rgb(0, 0, 0); letter-spacing: normal; text-transform: none; white-space: normal; word-spacing: 0px; text-decoration: none; -webkit-text-stroke-width: 0px; font-family: Tahoma, Verdana, Arial, Helvetica, sans-serif; font-size: 15px; line-height: 22px;"><span class="" style="font-size: 11px; font-family: verdana;">Director of the Madirel laboratory</span></div><div class="" style="caret-color: rgb(0, 0, 0); color: rgb(0, 0, 0); letter-spacing: normal; text-transform: none; white-space: normal; word-spacing: 0px; text-decoration: none; -webkit-text-stroke-width: 0px; font-family: Tahoma, Verdana, Arial, Helvetica, sans-serif; font-size: 15px; line-height: 22px;"><span class="" style="font-size: 11px; font-family: verdana;">Aix-Marseille University </span><span class="" style="font-size: 11px; font-family: verdana;">- Avenue Escadrille Normandie Niemen - F-13013 Marseille - FRANCE</span></div><div class="" style="caret-color: rgb(0, 0, 0); color: rgb(0, 0, 0); letter-spacing: normal; text-transform: none; white-space: normal; word-spacing: 0px; text-decoration: none; -webkit-text-stroke-width: 0px; font-family: Tahoma, Verdana, Arial, Helvetica, sans-serif; font-size: 15px; line-height: 22px;"><span class="" style="font-size: 11px; font-family: verdana;">Tél: +33(0)4 13 55 18 19 - Fax : +33(0)4 13 55 18 50</span></div><div class="" style="caret-color: rgb(0, 0, 0); color: rgb(0, 0, 0); letter-spacing: normal; text-transform: none; white-space: normal; word-spacing: 0px; text-decoration: none; -webkit-text-stroke-width: 0px;"><font face="verdana" class=""><span class="" style="font-size: 12px; line-height: 22px;">Email : </span></font><font color="#22bbea" face="verdana" class=""><span style="font-size: 12px; line-height: 20px;" class=""><a href="mailto:pascal.boulet@univ-amu.fr" class="">pascal.boulet@univ-amu.fr</a></span></font></div><div class="" style="font-size: 14px;"><br class=""></div></div></div></div></div><br class="Apple-interchange-newline"><br class="Apple-interchange-newline">
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<div><br class=""><blockquote type="cite" class=""><div class="">Le 28 janv. 2019 à 16:44, Paolo Costa <<a href="mailto:paolo.costa85@gmail.com" class="">paolo.costa85@gmail.com</a>> a écrit :</div><br class="Apple-interchange-newline"><div class=""><meta http-equiv="Content-Type" content="text/html; charset=utf-8" class=""><div dir="ltr" class=""><div dir="ltr" class="">Dear QE users,<div class=""><br class=""></div><div class="">I am trying to optimize (relax) Pd dimer (Pd2) as cluster placed on cubic lattice.</div><div class="">However I got a value of Pd-Pd bond length which is far too long (3.36 A) compare to the experimental one (about 2.6 A).</div><div class="">Am I doing something wrong? Here below the input file:</div><div class=""><div class=""><br class=""></div><div class="">&CONTROL</div><div class=""> calculation = "relax"</div><div class="">prefix ='Pd2'</div><div class=""> forc_conv_thr = 1.94469e-03</div><div class=""> max_seconds = 1.34369e+14</div><div class=""> nstep = 800</div><div class=""> pseudo_dir = "/home/pcosta/pseudo"</div><div class=""><span style="white-space:pre" class=""> </span>verbosity ='high'</div><div class="">disk_io ='none'</div><div class=""> tprnfor = .TRUE.</div><div class=""> tstress = .TRUE.</div><div class="">/</div><div class=""><br class=""></div><div class="">&SYSTEM</div><div class=""> a = 4.50000e+01</div><div class=""> degauss = 1.00000e-02</div><div class=""> ecutrho = 1.83747e+01</div><div class=""> ecutwfc = 1.46997e+00</div><div class=""><span style="white-space:pre" class=""> </span>lda_plus_u = .FALSE.</div><div class=""> ibrav = 1</div><div class=""> nat = 2</div><div class=""> nspin = 2</div><div class=""> ntyp = 1</div><div class=""> occupations = "smearing"</div><div class=""> smearing = "gaussian"</div><div class=""> starting_magnetization(1) = 2.00000e-01</div><div class=""> assume_isolated = 'makov-payne'</div><div class=""><span style="white-space:pre" class=""> </span>vdw_corr = 'grimme-d3'</div><div class="">/</div><div class=""><br class=""></div><div class="">&ELECTRONS</div><div class=""> conv_thr = 1.00000e-08</div><div class=""> diagonalization = "david"</div><div class=""> electron_maxstep = 800</div><div class=""> mixing_beta = 4.00000e-01</div><div class=""> startingpot = "atomic"</div><div class=""> startingwfc = "atomic+random"</div><div class="">/</div><div class=""><br class=""></div><div class="">&IONS</div><div class=""> ion_dynamics = "bfgs"</div><div class=""><span style="white-space:pre" class=""> </span>trust_radius_min=1e-5</div><div class="">/</div><div class=""><br class=""></div><div class="">&CELL</div><div class=""> cell_dofree = "all"</div><div class=""> cell_dynamics = "bfgs"</div><div class=""> press_conv_thr = 5.00000e-01</div><div class="">/</div><div class=""><br class=""></div><div class="">K_POINTS {automatic}</div><div class=""> 3 3 1 0 0 0</div><div class=""> </div><div class="">ATOMIC_SPECIES</div><div class="">Pd 106.42000 Pd.pbe-n-kjpaw_psl.1.0.0.UPF</div><div class=""><br class=""></div><div class="">ATOMIC_POSITIONS {angstrom}</div><div class="">Pd 16.194860 19.259990 18.659720</div><div class="">Pd 18.251640 18.665930 18.594650</div><div class=""><br class=""></div><div class="">Thanks.</div>-- <br class=""><div dir="ltr" class="gmail-m_6880443592494725121gmail_signature"><div dir="ltr" class="">Paolo Costa, Ph.D.<div class="">Postdoctoral Researcher</div><div class="">Department of Chemistry and Biomolecular Sciences</div><div class="">University of Ottawa</div><div class="">10 Marie Curie, Ottawa, ON K1N 6N5, Canada</div><div class="">Room number: DRO 326 (D'Iorio Hall)</div></div></div></div></div></div>
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